Improvement in fire-escapes



2Sheets--Sheet1. T. P. FURSYTH.

Fire-Escapes. N0 155 149 Patented Sept. 22,1874.

T iiif/g THE GRAPHIC DO. PHOTD-L|THJ9A+I PARK FLACILNJE 2 Sheets--Sheet 2* T. P. F0 R SYTH.

Fire-Escapes.

Pa'tented Sept. 22,1874.

\A/IIELEE E 25 X125 MVZ 1CD. PHOTO -'LlTH- 35 81 44 PARK UNITED STATES PATENT OFFICE.

THOMAS P. FORSYTH, OF NEW HAVEN, PENNSYLVANIA.

IMPROVEMENT IN FlRE-ESCAPES.

Specification forming part of Letters Patent No. 155,149, dated September 22, 1874; application filed August 7, 1874.

To all whom it may concern:

Be it known that I, THOMAS P. FORSYTH, of New Haven, in the county of Fayette and State of Pennsylvania, have invented a new and useful Improvement in Fire Escapes; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawing, forming part of this specification, in which Figure 1 is a view of my improved clamp provided with two stirrups as employed for descending a cord or cable, or as a fire-escape. Fig. 2 is a view of a second clamp provided with a belt and a single stirrup as rigged for ascending a cable; Fig. 3, a longitudinal sectional view of the two parts of the clamp detached; and Fig. 4 is a view of two clamps in position upon a rope as used in climbing.

Like letters refer to like parts in the several figures.

My invention relates to that class of articles known as fire-escapes, or clamps for ascendin g and descending a rope or cable; and it consists in a clamp, one jaw of which is concave, for receiving the rope, and the other convex, forclamping the same, the two being pivoted above by a pivot passing through ears or projections, or by lugs upon one jaw working in slots upon the ears of the other jaw; and also in passing the stirrup rope or strap attached to the end of one jaw through or over the other jaw, so that the weight of the person using the same may be made to act as a brake.

A and A represent the two clamping-jaws, the jaw A being concave throughout its inner surface, as shown at a, and curved, as at a to permit the passage and travel of the rope with which it is used. This jaw is also-provided with the ears or projections a by means of which it is pivoted to the opposite. jaw, and may be strengthened along its back between the lower arm and the curved portion a by a rib or fin, a The second jaw, A, may be smooth throughout its entire surface, which faces toward the other jaw, and is curved or bent inward at the point it, forming a cam-like projection, which takes into the bend a of the jaw A. The upper portion of the jaw A has also ears or projecting portions (F, by which it is pivoted to the projecting ears of the jaw A,

or the two jaws may be secured together by a rivet of suflicient strength, or a key, as shown at a or as more es eciall shown in Fi z2 by j 7 7 b 7 fixed pivots or projections taking into slots. WVhen the latter method of pivoting the jaws is adopted, the two jaws are hinged by simply extending one jaw at right angles to the other, and allowing the pivots to pass within the slots down to the bearing-points, when, upon bringing the clamps down upon the rope, the strain is such that the pivot is locked and cannot escape from the slot, as all drawing tendency is in a line which forces the pivots down upon the bearings. The jaw A is also strengthened by a nib or fin, a On the lower end of the clamping-jaw A is provided a projection, b, which may be either slotted, as shown in the drawing, or otherwise constructed, so that the stirrup strap or rope B may be attached thereto, and upon the lower end of the jaw A are two hook-like projections, I), provided with springs b similar to a snap-hook, over which the stirrup or rope may pass, so that when the weight ofa person, ascending or descending, is thrown upon the stirrup, the strap or rope of which passes over said projections, the jaw A is forced against the jaw A in such a manner as to cause the same to bite firmly upon the rope and act as a safety-brake, for should any person from any cause ascending or descending a rope become nnconcious, or in any manner permit the weight of the body to rest upon the stirrup, the strap of which passes over the projections on the clamp A, instead of transferring the weight to the stirrup passing directly from the jaw A, the clamp instead of slipping will be forced tight against the rope, and the body cannot descend farther.

Where two of these clamps are used in climbing, one is rigged with a single stirrup passing over the projections upon the clamp A, as more especially shown in Fig. 2, and to the upper portion of the clamp A a strap or other suitable device is attached by means of a ring or similar means, and to said strap a belt or band, which may be passed around the body, which will enable the user to have possession and control of the second clamp under all circumstances.

Where a single clamp is used, as shown more especially in Fig. 1, when the same is intended for afire-escape, or for simply descending arope,

two stirrups are attached to the same clamp,

and both are directly attached to the jaw A one by means of a slot, as before specified, and passing over the projections or through the spring-catch upon the clamp A, and the other from a loop, ring, or, swivel attached to the projections on the lower portion of the clamp, as shown at B This enables the weight to be at all times placed positively on the jaw A, and sufficient weight transferred to the second jaw A to increase or decrease the bite upon the rope, whereby the user may descend more or less rapidly, as he desires. B B indicate the straps or ropes, and B the stirrup, U being a belt, which may be passed around the body, and is attached to the clamp A at its upper portion, as shown.

The operation of the above-described devices is as follows: When the single device is used in descending a rope or as a fire-escape, the one rigged with two stirrups, as shown in Fig. 1, is employed. The feet are placed within the stirrups, the strap or rope of one of the stirrnps passing over the projection upon the jaw A, whereby the brake is formed; and, if desired, the body can be still further secured to the clamp by passing a belt, as shown in the second figure, and connecting the same with the clamp. The weight of the person is taken mainly upon the stirrup, passing directly from the jaws A, and only so much weight thrown upon the stirrup, the strap of which passes over the clamp A, as will cause the jaw A to bite upon the rope with sufficient force to prevent a too rapid descent. If at any time it is desired to check the descent, the whole weight of the body may be thrown upon the stirrup, the rope of which passes over the clamp A.

In climbing, in addition to the clamps shown in Fig. 1, a similar clamp, rigged like that shown in Fig. 2, may be employed, or either of the clamps may be employed rigged with a single stirrup alone, in which case the stirrupstrap of both clamps will pass over the second jaw A, so as to act as a positive brake when the weight is upon the said clamp.

One stirrup-strap should be longer thanthe other, and the clamps are used following one another up the line of rope, as follows: The first or upper clamp is relieved of the weight, which is transferred to the second or lower clamp, the first clamp is then raised to the height of the arm above the head, when the weight is transferred to the stirrup of that clamp, the straps passing over the jaw acting as a brake, the same will become firmly attached to the rope, and the weight of the body is sustained thereon until such time as the second clamp is brought up in close position thereto, which can be readily done as the weight is removed from said clamp. Thus the weight is shifted from clamp to clamp alternately, which relieves the brake, and the clamps are raised in regular succession.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s-

1. The jaw A, having a curved inner surface, a and 00 in combination with the jaw A, havin g the convex surface 01/ substantially as and for the purpose specified.

2. The combination of the concave jaw A, having the slotted ears a and the convex jaw A, having the lugs or projections for engaging with the slotted ears, substantially as and forthe purpose specified.

3. The jaw A, having the slotted projections for the attachment of the stirrups B, in combination with the jaw A, having the projecting hooks or lugs 11 for the passage of the stirrup-rope B whereby a brake is formed, substantially as and. for the purpose specified.

In testimony whereof I, the said THOMAS P. FORSYTH, have hereunto set my hand.

THOMAS P. FORSYTH.

Witnesses:

JOSIAH KURTZ, JOHN KURTZ. 

